For dummies
One single exe. ( contain server and viewer)
1) copy exe to both pc
2) enter gmail account and password ( need to be the same on both sites)
3) wait until support led is green
4) The person who want to share his desktop press "show desktop"

For the experts.
-The exe is a 7zip archieve.
-Text, background, logo ,icon can be customized.
-The server is the SC ( update august 2009)
-The viewer is the standard ultravnc 1065 viewer
-The Google Talk component is the nat2nat ( post #61784) component modified for SC.
-Encryption is buildin DH key exchange
-socket comperssion is used ( the compression is adaptive, if data is already good compressed by vnc, it disable himself)
-Size is bigger ( 1MB) , archieve contain server and viewer

(What's the start time doing in the title)
When server and viewer run on the same pc, the title need to be different.
Adding the time insure it's different.

helpdesk.txt
--------------
changes are in red*localhost:9999 required for GT
*[GTALKACCOUNT] this preset the account, input box is removed if set.
User only need to enter the password
*[GTALKSUPPORTACCOUNT] this allow the user and support account to be different. You can use a different account on viewer and server site,
on the server site you put it in the helpdesk.txt
The # in front need to be removed, i used it to disable an option.

[BALLOON1TITLE]
Establishing connection ...
[BALLOON1A]
5 min try period
[BALLOON1B]
If it fails, the software will remove himself
[BALLOON1C]
from your system.
[BALLOON2TITLE]
Connection active.
[BALLOON2A]
Warning, your desktop is remote visable
[BALLOON2B]
You can break the connection any time
[BALLOON2C]
by using the close button

If there is no 3rd party firewall installed or disabled temporarily, and Windows Firewall is also disabled temporarily, then everything happens super smooth.

my review:
vnchooks.dll, schooks.dll passses McAfee Enterprise Anti-Virus guard+scan, on Vista, and on XP,
but 'vnchooks.dll' causes extra warnings from firewall softwares, when it tries to create hook, i guess.

'uvnc_SC_GT.exe' after running, decompresses the 'UltraVnc_GT.exe' (uvGT), which after connecting to gmail, tries to do local connection on local net with their local IPs for computers 1st (uses icmp, UDP packets as well).
but since i had restriction rules placed on such local connections,
so sc-gt tries to use the external internet ip to connect back to local computers, and connects.

it connects to google at port 5222, 80 and then also tries port 19302, 19295, 19294, etc.

it connects by usin my external internet ip, with random port (at different time) to the computer that is running this.

like Rudi said, uvnc srvr connects to uvGT using port 9999, and uvGT connects to uvnc viewer using port 5500.

on Vista, the UAC ( the Univeral Annoying Champion ) didnt appear, it was executed from Admin account.

on Vista, a message from 'Windows Firewall' popped up and asked for user's permission to allow it, which i did allow, and 3rd party firewall also asked for permission on each component (uvnc srvr, viewer, uvGT, vnchook) when it ran.

uvGT on XP, once gave some warning about Vista's UAC ! i guess.

on Vista, crashed once, then uvnc viewer was still running, had to exit/close it.

on XP, after 'close', uvnc viewer was still running !

tried to make the same PC, a server once & then a viewer once, so that must have caused such remaining running instances, or a bug?

in neither case, the LED of encrypted tunnel, was not ON, was that bcuz i used same gmail on both side ?

each of this PC had its own Anti-Virus, Firewall installed. One is XP+SP3, another is Vista+SP2. both behind Wireless Router (NAT), DSL (with dynamic internet IP).

But:
-it works veeeeeeeery slow (hextile-encoding with full colors, do you want this???)
-it works only on admin-accounts (is it possible to use the real, full UVNC winvnc.exe with ultravnc.ini?)
-the sc (winvnc.exe with 244 kb) is not really new (1.0.0 RC 20.3 - build in 2006???) shown build date 26.08.2009
-the helpdesk.txt-file could not deleted/moved/changed easy by the 7-Zip Manager
-gmail account could set, why not the password for the account??? (sending to a friend, starting the file and be happy )
-vncviewer in listen mode must be finished manually, not so practical

thanks for your fast answer.
I work with win XP Prof. SP3 in user mode, and if i start your gt-file my os told that i `v not the permission to start the programm.
After changing from normal user mode to admin user mode it works fine.

How can i fix the gmail account and password and change the helpdesk.txt?

I am have numerous problems with the program closing on my Vista machine. I am running Vista Ultimate SP1. It stays up fine on My XP Pro machine. On the vista machine I can launch the program and sign on, but when the remote machine connects and pressed the share desktop button, the local program on my vista machine either disconnects or just closes.

Also about every third time (really random) when press the sign on button on my vista machine the program gets trapped by DEP and fails.

I currently use Teamviewer to help out the people in my company, Im the tech guy but have no formal training so Im still pretty noobish with this. We all work from home and a lot of these people have zero computer skills, hence the reason I use teamviewer for its easy. Teamviewer tends to lock up from time to time so I gave this option a try but it runs slower then TV. Id like to give this a try but another issue is I cant access other monitors on the remote pcs. So is there anyway to see the other monitors if needed and maybe speed it up a little?